1. Technical Field
This disclosure relates to wireless communication devices, and more particularly to single radio wireless devices communicating on multiple radio access technologies.
2. Description of the Related Art
Wireless networks continue to evolve as new communication technologies develop and standardize. Wireless network operators can deploy new communication technologies in parallel with earlier generation communication technologies, and wireless networks can support multiple communication technologies simultaneously to provide smooth transitions through multiple generations of mobile wireless devices. A representative wireless network may include simultaneous support for the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) wireless communication standard and the 3rd Generation Partnership Project 2 (3GPP2) CDMA2000 1× (also referred to as 1×RTT or 1× or IS-2000) wireless communication standard. This representative “simultaneous” wireless network can support circuit switched voice connections through a first wireless network that uses the CDMA2000 1× wireless communication protocol and packet switched connections (voice or data) through a second wireless network that uses the LTE wireless communication protocol. The 3GPP wireless communications standards organization develops mobile communication standards that include releases for Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE) and LTE Advanced standards. The 3GPP2 wireless communications standards organization develops mobile communication standards that include CDMA2000 1×RTT and 1×EV-DO standards.
Some mobile wireless devices may include functionality to support simultaneous access to more than one wireless network and thus more than one radio access technology. Some of these devices include dual circuits to access two such networks. Although useful, some of these dual devices consume a great deal of power when compared to their single circuit counterparts.
More particularly, the single circuit devices which may be referred to as single chip device or single radio devices, may also support access to more than one radio access technology and thus more than one wireless network. However, the single radio devices may only access one network at a time. For example, a single radio user equipment (UE) device may connect to or camp on an evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (eUTRAN) of the LTE wireless network and also connect to or camp on a radio access network (RAN) of the CDMA2000 1× wireless network, but not to both wireless networks simultaneously. Some of these UEs may camp on one of the networks and then tune away from that network at some interval to check for incoming messages or calls on the other network.
However, there may be issues that arise when the UE tunes away from the first network because the first network may have no knowledge that the UE has tuned away. For example, the first network may waste downlink capacity by unnecessarily allocating downlink resources to the UE during the tune-away operation. As another example, the first network may penalize the UE by reducing its future downlink allocations, for example, since the UE does not respond to commands from the first network during the tune-away operation.